1. Field of the Invention
The present invention relates to a vehicular communication device, especially suitable for urgently reporting road emergencies.
2. Description of Related Art
A conventional vehicular communication device is disclosed in U.S. Pat. No. 3,986,119. The device has a distress select switch having four positions. Each position of the switch is used for inputting a distress signal (police, accident, towing, service, etc.) corresponding to a rescue item which a user needs. When the user selects one of the positions in an emergency, the selected distress signal is transferred to a control center through roadside relay stations. After receiving this signal, the control center determines the position of the user. The control center then dispatches help to the user, and simultaneously transmits an acknowledgement signal to inform the user that the message has been received. After the communication device receives the acknowledgement signal, an acknowledge indicator of the device is activated. Thus, the user can make sure that the user's message has been surely received.
However, according to the above-mentioned communication device, the user can select only one of the four distress signals with the distress select switch. In other words, the user can not select plural signals at a time. For example, in case that the user was in a car accident, the user generally needs an ambulance, the police and road service. The user has to request these three services one by one even in such an emergency, going through the whole process each time. This requires a lot of time to request help.
In considering the above problems, the inventors have thought that a vehicular communication device may include an exclusive switch besides the above-mentioned distress select switch to enable a user to report plural requests at a time. According to this feature, when the device is used for reporting an emergency which happened, for example, while driving a vehicle, an exclusive switch for requesting an ambulance and the police, an exclusive switch for requesting the ambulance, the police and a road service, and so on, are provided. However, in this case, it is hard to distinguish one switch from the others because the number of the switches is large. Moreover, these switches must be miniaturized due to space limitations. This reduces the chances of proper operation by an operator in an emergency.
Since the user is generally frightened in an emergency, a large number of switches easily causes incorrect operation in that the user operates an incorrect switch. Therefore, such incorrect operation needs to be canceled somehow.
Moreover, when the number of the distress signals is plural, it is desirable that the device enables the user to make sure that each signal has been received by the control center.